A USB connector is widely applied in electronic devices, such as data cards, and USB flash drives (e.g., a U drive), and these data cards and USB flash drives are commonly applied in electronic products such as a mobile phone, a walkie talkie, a telephone, and a computer. The data cards and USB flash drives are frequently inserted and removed in use; therefore, there are high requirements for the structural strength and grounding reliability of the USB connector.
Currently, a USB connector generally has six pins, four of which are function pins used to transmit a signal or data, and the other two are grounding pins used to ground a shell element of the USB connector and further improve welding strength of the USB connector. In the process of inserting and removing the USB connector, welding joints of the two grounding pins become major force-bearing points for insertion and removal stresses. It can be learned from failure analysis of USB connectors that in most failure samples a crack occurs at a welding joint of a grounding pin because grounding pins are major force-bearing points. If a problem occurs at a welding joint of a grounding pin, on one hand, grounding reliability of the USB connector is affected, and on the other hand, structural strength of the USB connector is also affected, resulting in a failure or malfunction of the USB connector. Especially, during use by a user, in a case in which incautious use occurs, such as incorrect insertion, falling down, or bump, a welding joint loosens more easily, impairing reliability of the USB connector. Therefore, under the premise that the grounding reliability of the USB connector is ensured, it is crucial to ensure structural strength reliability of the USB connector.
In addition, a main structure forming a current USB connector, namely, a USB head, is generally connected to a printed circuit board (PCB) of the USB connector by means of welding or by using an additional mechanical structure, for example, a fixed lug, so as to implement positioning of the USB head and the PCB. However, in a case in which positioning is implemented by means of welding, because of a reliability problem of welding techniques, mutual positioning between the USB head and the PCB may become unreliable, thereby affecting structural strength of the USB connector, resulting in a failure or malfunction of the USB connector. In a case in which positioning is implemented by using an additional mechanical structure, for example, a fixed lug, structural complexity is obviously increased, and thereby costs are undesirably increased. Especially, during use by a user, in a case in which incautious use occurs, such as incorrect insertion, falling down, or bump, mutual positioning between the USB head and the PCB may easily become unreliable, impairing reliability of the USB connector.
FIG. 1 schematically shows a USB connector in prior art 1. A terminal of a male connector of a USB head is connected to a female connector to achieve the purpose of working. The male connector of the USB head is welded on a PCB by using four weld legs on the USB head, which not only achieves the effect of grounding, but also achieves the effect of mutual positioning between the USB head and the PCB. However, for the USB connector in prior art 1, the USB head is welded on the PCB to implement grounding and positioning between the USB head and the PCB; however, because of a reliability problem of welding techniques, for example, faulty welding, the USB connector has undesirable structural strength and grounding reliability. In addition, the USB head is welded on the PCB; therefore, the overall thickness of the USB connector is relatively large, which adversely affects product miniaturization and cost reduction of the USB connector. Moreover, the USB head of the USB connector in prior art 1 is welded on the PCB by using the four weld legs on the USB head, and the four weld legs increase the overall length of the USB head. As a result, the total length of the USB head reaches 21.5 millimeters (mm). During use by a user, an excessively long USB head more easily causes improper use, for example, incorrect insertion. Besides, the USB head is relatively long, and therefore the overall rigidity of the USB head is relatively low, making it easy to bend and deform during use, thereby resulting in a failure or malfunction of the USB connector. In addition, compared with a current USB connector that usually has two grounding pins, the USB head of the USB connector in prior art 1 has four weld legs, and therefore, two weld legs are added. As a result, the excessive long USB head and the two added weld legs both adversely affect product miniaturization and cost reduction of the USB connector.
FIG. 2A and FIG. 2B schematically show a USB connector in prior art 2. An edge connector, referred to as a golden finger, of a PCB is connected to a female connector of a USB head, so as to achieve the purpose of working. A lug is additionally arranged on a metal housing of the USB head, and the lug is fastened at a shell element of the USB connector by using a screw to achieve the purpose of grounding the shell element of the USB connector. However, for the USB connector in prior art 2, grounding is implemented by fastening the lug of the USB head to the shell element of the USB connector, thereby causing the problem of complex structure and unreliable grounding. Moreover, there is no positioning between the USB head and the PCB; therefore, structural strength of the USB connector is undesirable. In addition, for the USB connector in prior art 2, the USB head is connected to the shell element of the connector by using the lug additionally arranged on the metal housing of the USB head, and therefore the additionally arranged lug increases the overall length of the USB head, and the total length of the USB head reaches 18 mm. During use by a user, an excessively long USB head more easily causes improper use, for example, incorrect insertion. Besides, the USB head is relatively long, and therefore the overall rigidity of the USB head is relatively low, making it easy to bend and deform during use, thereby resulting in a failure or malfunction of the USB connector. The excessive long USB head also adversely affects product miniaturization and cost reduction of the USB connector.
With the saturation in the market of data cards and USB flash drives and intensifying competition among manufacturers, the industry urgently needs a USB connector that has improved structural strength and enhanced grounding reliability and can achieve the objectives of product miniaturization and cost reduction.